Rabl,W.; Katzgraber,F.; Kneubuehl,B.P.;

Tandem loading of a cartridge of the same caliber is possible only if the diameter of the barrel is sufficiently wide. This requirement is met by the .22 long shot Anschutz miniature clay pigeon gun. Ballistic experiments with tandem-loaded cartridges of the same caliber as those loaded in the normal way showed the bullet of the regularly loaded cartridge to impact the muzzle-loaded cartridge. On firing a shot, the bullet of the posterior cartridge penetrates the anterior one, expanding the case of the first cartridge to the diameter of the barrel and disintegrating the bullet. Regardless of whether the muzzle-loaded cartridge is ignited or not, the discharge speed of the projectiles (v0) is considerably below that of single shots. Calculations yielded a theoretical reduction by about 60%. In accordance with the formula E=1/2mv2, in terms of the energy released, the elevated mass of the projectile is of secondary importance compared with the reduction of v0. Although the “projectile” mass is more than twice the normal rate, the energy density is significantly reduced and the biological effect is attenuated. This also became apparent in the failed suicide attempt of a 43-year-old male who used a miniature clay pigeon gun to shoot himself in the forehead at a range of a few centimeters. He had inserted a second cartridge, base to head with the first cartridge, in the factory-bored barrel of the gun. The leading cartridge was destroyed by the regularly loaded one. The pierced and expanded case of the leading cartridge was found nearby the injured man and was at first taken to be the jacket of a larger-caliber bullet

Int J Legal Med 1999 112(1):58-61